The structures of the present invention represent a new class of doubly intercalating derivatives of daunomycin and adriamycin. Recent studies from several laboratories [especially that by Canellakis et al., Biophysica Acta, 418, 277-314 (1976)] have demonstrated that this mode of DNA binding is associated with important biological properties (especially cytotoxic and antitumor properties of a series of bis-9-acridyl compounds). Use of the helical DNA-adriamycin molecular model, which has proven useful in the past in this project, suggested that bis-derivatives of the type disclosed could form a unique doubly intercalated complex.